The lifting of a four-decade ban on U.S. oil exports could boost Colorado’s global trade fortunes — but the timing of when that happens is anybody’s guess.

“In the next 12 months, it is unlikely to have much influence at all. It won’t play much of a role,” said Mark Snead, an economist at RegionTrack in Oklahoma City.

That’s because the world is awash in petroleum. But long-term, as prices recover and more shipping infrastructure gets built, Colorado petroleum producers could benefit.

And they would need to sell only a fraction of their output abroad to catapult into the ranks of the state’s top exporters.

Colorado exports last year were up only 5 percent from the 2006 totals reached before the recession hit. Part of that reflects shifting demand for the state’s higher-end manufactured goods.

Those tend to fall in and out of favor — remember StorageTek in Louisville, Eastman Kodak in Windsor, Sanmina-SCI in Fountain and so on?

Gaining a whole new product category with lasting appeal in foreign markets excites trade advocates in the state.

“We are starting to gather people from our network to put together an interest group of companies that would like to talk about global energy,” World Trade Center Denver president Karen Gerwitz said.

Colorado exported $8.4 billion in goods last year across nearly 100 categories. But just four groups accounted for more than half of all exports, according to WISERTrade numbers provided by the World Trade Center Denver.

At $1.3 billion, Colorado’s largest export category is optical, photographic and measuring devices, a group that also includes surgical instruments and medical devices.

It is followed by industrial machinery, including computers, at $1.2 billion and electric machinery, including sound and television equipment, at $1.1 billion.

Meat to eat, primarily beef, rounds out the top-export category at $1 billion.

At $50 a barrel, producers in the state would need to sell around 26 million barrels of oil in foreign markets to reach the $1.3 billion export mark.

That is just over a fifth of Colorado production this year, based on an extrapolation of U.S. Energy Information Administration counts through the first nine months of the year.

At $75 a barrel, Colorado producers would need to find foreign buyers for 17.3 million barrels, or 14.7 percent of 2015 production. And if oil ever regains the $100-a-barrel mark hit in the middle of last year, it would take 13 million barrels, or around 11 percent of the state’s 2015 production.

“The Denver-Julesburg producer must find a price that is at least $12 a barrel better to make them indifferent between exporting and sending that barrel to a local refiner,” said Sarp Ozkan, a senior energy market analyst at Ponderosa Advisors in Denver.

Since the export ban was lifted Dec. 18, the gap between the price of a barrel of domestic and nondomestic oil has essentially vanished.

“These spreads just do not exist at the moment,” Ozkan said.

One argument offered against lifting the export ban is that the country remains a net importer of oil. About 46 percent of the oil that U.S. refineries processed last year came from abroad, so why not just use what is produced in the U.S.?

But much of the oil drawn from shale formations in places such as the Denver-Julesburg Basin, northeast of Denver, is “sweet,” or of a lighter grade.

Domestic refineries, not anticipating the shale boom, made major investments to process heavier crudes from Canada, Venezuela and elsewhere.

For example, Suncor Energy spent $445 million in upgrades at its Commerce City refinery to handle extra heavy crude from tar sands in Canada. That spending wrapped up in 2006, right before a drilling boom next door in Weld County would unleash a river of sweet crude.

To use a beer analogy, Colorado’s oil producers are bottling pale ales, while U.S. refineries have a taste for dark stouts.

Refiners have argued that lifting the export ban only increases their risks and makes it harder to justify the investments needed to create gasoline and other fuels from lighter grades of crude.

Refineries do mix the lighter oil with the heavier stock to get a more palatable mix. And the Suncor refinery, along with the HollyFrontier refinery in Cheyenne, remain prime consumers of Colorado oil, Ozkan notes.

A small amount of Colorado oil heads west on rail cars, but most of what isn’t going to the local refineries moves out of the state via pipelines to Cushing, Okla. From there, it can reach refineries along the Gulf Coast or, should foreign buyers emerge, move onto tankers.

Assuming similar costs to lift a barrel out of the ground, Texas oil would have an advantage over Colorado oil because of its proximity to shipping terminals.

On Wednesday, a Texas company said it had struck a deal to ship 600,000 barrels of light crude at the start of the year to a Dutch buyer for use in a Swiss refinery.

Ozkan said an important threshold to watch for is when total U.S. oil production, now at around 9.1 million barrels a day, exceeds 12.5 million to 13 million barrels a day.

That represents what U.S. refineries can absorb, less the heavier crude they bring down from Canada. Any surplus oil will have to find somewhere else to go.

Natural gas exports weren’t limited to the degree that oil was, although they have to ship through federally approved facilities, the handful of which are primarily located along the Gulf Coast.

And producers on Colorado’s Western Slope, where natural gas dominates, are eager to find new markets.

“The emphasis has been on development of the liquefied natural gas terminals,” said David Ludlam, executive director of West Slope Colorado Oil and Gas Association.

West Slope COGA is throwing its weight behind a specific LNG terminal — Jordan Cove in Coos Bay, Ore. The facility would liquefy natural gas, basically cooling it so it can be compressed and loaded onto ships for transport.

Big natural gas finds in Ohio and Pennsylvania have eliminated demand back East for Colorado natural gas. A few industrial users bought Western Slope reserves after natural gas prices cratered in 2009, but continued weakness scared off more purchasers.

Environmental sensitivities and transportation difficulties make it unlikely that industrial plants that need hydrocarbons, say for fertilizer or plastics, would ever locate out that way.

Given Jordan Cove is not set to start construction until 2019, the most likely export destination for Western Slope natural gas will be Mexico, via pipeline.

China is looking to move away from its reliance on coal because of worsening air quality, while Japan is trying to get away from nuclear since the 2011 disaster at Fukushima.

“China would be interested in trying to get some access to natural gas, but China’s growth is diminishing,” said Keith Maskus, a University of Colorado professor who specializes in international trade.

I have worked at The Post since late 2000. My beats include residential real estate, economic development and the Colorado economy. Other publications where I have worked include Financial Times Energy, The Denver Business Journal and Arab News. My parents immigrated from northern Italy, although my great grandparents came to Central City in the late 1800s.